Tension control mechanism



sin, 5%, 3&5. c. J. ARRiNGTON p l TENSION CONTROL MECHANISM Filed Nov. 22, 1944 IN V EN TOR. if (d/V450 L/. JFK/N6 7'0/1 ATTORNEY Patented Oct. 30, 1 945 TENSION CONTROL MECHANISM Conard .I. Arrington, Winnsboro, S. C., assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application November 22, 1944, Serial No. 564,657

4 Claims.

The present invention relates to mechanism for controlling the tension of strands of roving. yarn or thread.

The tension control mechanism of the present invention may be associated with various forms of apparatus in which strands are advanced from a source of supply to a take-up package, but has been developed more particularly for use in connection with spinning machines of the type in which strands are supplied to a plurality of spinning devices from a single let-off roll or tube.

In such spinning machine it is common practice to employ a jack tube having a number of separate packages of roving or yarn wound thereupon, and to advance the strand from each packto the slight variation in the shape and size ofthe individual packages and to other causes.

As a result of this variation in tension some of the advancing strands will be taut while others will be slack and will sag noticeably between their supply package and the strand advancing. feed rolls, and this slack may become great enough to interfere with the travel of a strand.

,The primary purpose. of the present invention is to provide extremely simple means for automatically controlling the tension of these strands whereby when a strand becomes slack andsags appreciably its speed of. travel will be automatically increased to take up such slack.

Such a tension control is secured, in accordance with the present invention, by providing a first pair of rolls having a strand feeding nip.

and a second pair of rolls having a strand feed-.

ing nip and also-one or more clearance spaces between the roll surfaces, whereby a slight shifting of a strand lengthwise of this second pair of rolls will move it into or out of engagement with the nip of these rolls.

One pair of rolls is driven at a slightly faster surface speed than the other pair of rolls and from the control of one pair of rolls to the other.

as its tension varies is extremely simple and conthe arrangement is such that as long as a strand sists of an inclined'fixed guide along which the i strand will slide by gravity as it sags from the straight line position. The construction and arrangement of the fixed guide is such that when the strand is in a taut straight line position it will be directed by such guide to the nip of the second pair of rolls, but when the strand becomes slack enough to slide down the fixed, inclined guide it will be shifted lengthwise of this second pair of rolls out of their nip and into the adjacent clearing space, to thereby place the slack strandunder the control of the faster first pair of rolls.

The construction and operation of the ten-- sion control mechanism of the present invention will be more fully understood from the following description when read in connection with the accompanying drawing wherein:

Fig. 1 is a top plan view of a conventional type of ring spinning frame having the tension oontrol mechanism of the present invention associated therewith.

Fig. 2 is a sectional view taken on the ,line 2-2 of Fig. 1; and

Fig. 3 on a larger scale is a front view of strand guiding means shown in Figs. 1 and 2.

The tension control mechanism of the present invention may be associated, not only with a ring spinning frame as shown in the drawing, but also with fly twisting frames and other types of machines where it may be desirable to control the tension of an advancing roving, yarn or thread as the same is unwound from a source of supply, and drawn forward therefrom.

The ring spinning frame shown in Figs. 1 and 2' of the drawing comprises the jack tube Ill having wound thereupon the separate strand packages H. These packages as shown rest upon the feed rolls l2 and I3 which are driven, by means not shown, at a surface speed which bears a definite relation to the speed of other operating parts of the spinning machine.

In most spinning frames one or more pairs of nip rolls are provided for pulling the strand forward from a source of supply and for controlling the speed at which such strand is delivered to the spinning spindle. When such spinning mechanism is employed to spin a roving two or more of these pairs of nip rolls are usually provided for the purpose of drawing or attenuating the roving before it reaches the spinning spindle. In the construction shown two pairs of these strand advancing rolls are shown. The front pair of rolls comprising the bottom roll I and top roll I! may be of usual construction. The back pair of rolls comprises the lower roll l6 which may be of usual construction and a top roll I! of special construction to be described. The front pair of rolls .is driven at a slightly faster surface speed than the back pair of rolls.

The strands i8 supplied by the packages II are drawn forward from their respective packages between the back rolls I! and I1 and front rolls .H and II. They then pass downwardly to'pigtail guides ll of usual construction and each of which is supported by the rail 20 directly above the longitudinal central axis of a power driven spinning spindle 2|, which is driven by the whorl 22. Each strand it passes from a pigtail 2| to the traveler 23 that is slidably mounted on the ring 24 mounted on the ring rail 25. The strand I! after being twisted by the action of the traveler 23 is wound upon the spindle 2| to form the package 26. The mechanism so far described by reference numerals with the exception of the top back roll ll may be of usual construction and works in a well known manner.

The top back roll I1 is cut away at spaced points as indicated by '21, there being one cut 7 away portion for each spinning spindle as will be apparent from Fig. 1. The construction of the back rolls l6 and I1 is such that as long as a strand I8 is taut and travels in a straight path from its let-oil. package H to the pairs of feed rolls, it will be engaged and pull forward by the nip-of the back rolls, but when astrand becomes slack so that it sags somewhat from the straight line position it will be shifted slightly lengthwise of the back rolls out of the nip of these rolls and into the adjacent clearance space provided by the cutaway portion 21 of the top back roll.

This shifting of the strand into and out of engagement with the nip of the back rolls is effected automatically in accordance with the present invention by providing each of the strands I8 with a specially constructed fixed guide positioned between the supply packages I I and back rolls. These guides are carried by the fixed rail 29 secured to a portion of the spinning machine frame so as to support these guides near the back rolls as shown. The construction of the guides 28 may be varied considerably from that shown in the drawing provided they have a seat forming portion disposed so that it will guide the taut yarn to the nip of the back rolls and an inclined portion 30 along which the sagging slack strand will slide under the influence of gravity, so that as the strand slides down this inclined portion 30 it will be directed by the same into aclearance space'provided by the cutaway portion 2'! of the top back rolls.

As above stated the front rolls are driven at a slightly faster surface speed than the back roll. If a roving is being suppliedand is engaged by the nip of both pairs of rolls it may be drafted slightly, but this is incidental to the main purpose of these rolls. If the strand It has very little stretch and is engaged by the-nip of both pairs of rolls, thenit will have to slip relatively to one pair of rolls in order not to break. This trated in Figs. 1 and a of the drawing, this strand will be guided into the clearance space 21 between the rolls l8 and IT to relieve it from the control of the rear rolls and permit this strand to be pulled forward by the nip of the faster front rolls II and It.

It will therefore be seen that as long as a strand I8 is taut it will be pulled forward by the nip of the back rolls but when it becomes slack it will be pulled forward by the nip of the faster front rolls so that its slack will be taken up,

whereupon the strand will again come under the control of the slower back rolls. It will also be seen that the fixed guides serve to direct the strands to the nip of the back rolls when the strands are taut and to the clearance spaces between these rolls when they are slack.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

l. Tension control mechanism comprising in combination, a source of strand supply, a pair of front rolls having a strand feeding nip, a pair of back rolls having a strand feeding nip and an adjacent clearance space between the roll surfaces, means for driving the front rolls slightly faster than the back rolls, and a. fixed guide constructed and arranged to direct a taut strand to the nip of the back rolls to be advanced thereby and a sagging slack strand to the clearance space between these rolls so thatlit will be advanced by the faster front rolls. l'

is readily accomplished by making the pressure exerted by the nip of the front rolls somewhat less than the pressure exerted by the nip of the back rolls.

The operation of the tension controlled mechanism of the present invention is as follows: As 4 long as a strand I8 is taut as it passes from the supply package II to the feed rolls it will engage the pocket portion of the guide 28 and be guided thereby to the nip ofthe back rolls, as is the case with three of the four strands shown in Figs. 1 and 3 of the drawing. If however, a strand It becomes slack so that it sags sufliciently to slide down the inclined portion 30 of the guide,

as shown in the case of the fourth strand illus- 2. Tension control mechanism comprising in combination, a source of strand supply, a pair of front rolls having a strand feeding nip, 9. pair of back rolls having a strand feeding nip and an adjacent clearance spaced between the roll surfaces, means for driving the front rolls slightly faster than the back rolls, and an inclined fixed guide down which the strand will slide by gravity and arranged to direct a taut strand to the nip of the back rolls to be advanced thereby and a sagging strand to the clearance space between these rolls so that it will be advanced by the faster front rolls;

3. Tension control mechanism comprising in combination, a. source of strand sup ly. a pair of rolls having a strand feeding nip, a second pair of rolls having a strand feeding nip and an adjacent clearance space between the roll surfaces, means for driving one pair of rolls at a slightly faster surface speed than the other, and

an inclined fixed guide down which a slack strand .devices from a single let-01f roll; mechanism for controlling the tension of these strands comprising a pair of front rolls having a strand feeding nip, a pair of back rolls having a strand feed nip and also clearance spaces between the roll surfaces, means for driving the front rolls slightly faster than the back rolls, and an inclined fixed guide along the path of each strand adapted to direct a taut strandto the nip of the back rolls and a slack sagging strand to one of said clearance spaces between these rolls.

CONARD J. ARRINGTON. 

